Profile grinding wheel dressing device



' Sept. 5, 1967 ST DE ETAL 3,339,537

. PROFILE GRINDING WHEEL DRESSINC DEVICE Filed Sept. 5, 1964 2Sheets-Sheet 1 Inventors GERHA AND 8 Gam EPP'N ATTaRwYs Sept. 5, 1967 G.STADE ET AL 3,339,537

' PROFILE GRINDING WHEEL DRESSING DEVICE Filed Sept. 5, 1964 2Sheets-Sheet 2 Fig. 4 v

10 van/01's GERHARD AND Gilw-rea REPPIN 'nwmww 7:,

A 1 TORIV vs United States Patent Ofiice 3,339,537 Patented Sept. 5,1967 3,339,537 PROFILE GRINDING WHEEL DRESSING DEVICE Gerhard Stade,Berlin, and Giinter Reppin, Olfenbach am Main, Germany, assignors tHerbert Lindner G.m.b.H. & Co., Berlin-Wittenau, German y Filed Sept. 3,1964, Ser. No. 394,179 Claims priority, application Germany, Oct. 3,1963,

13 Claims. (in. 12s 11 This invention relates to the dressing ortrimming of profile grinding wheels used to impart predeterminedcontours to mechanical elements such as gears and the like. Moreparticularly, the present invention relates to an improved apparatus forautomatically controlled diamond dressing of profile grinding wheelswith the reduction of the path of movement of the tracer stylus.

Hitherto, automatically controlled diamond dressing of profile grindingwheels has been effected by transmitting the displacement of a tracerstylus, guided along a template, through the medium of cross slide meanson which the tool holder for the diamond tool is mounted. This crossslide means comprises one slide which is movable parallel to the axis ofthe profile grinding wheel while the other slide is movableperpendicular to the axis thereof. This known method has thedisadvantage that the dressing diamond, with respect to theperpendicular frame of reference of the tool slides, must producesharply curved segments along the profile to be shaped and thus mustcome into engagement with the grinding wheel at several places along itscutting edge. As a result, radial diamonds must be used and these, dueto their shape, are not effective to trim sharp or steep profiles unlesstheir sockets are at least partly ground away. Furthermore, a specialswivelling device must be provided in order to be able to maintain theaxis of the radial diamond always approximately perpendicular to theprofile of the grinding Wheel, no matter at which place on such profilethe diamond is working. A particularly complicated control means for thedressing diamond is required for this purpose.

An object of the invention is to provide a device for automaticallycontrolling dressing of profile grinding wheels and with which the pathof travel of the tracer stylus is substantially reduced.

In accordance with the invention, the dressing diamond is fed parallelto a straight main flank line which is coordinated with the respectiveprofile and which is inclined to.the perpendicular on the axis of thethread to be produced, while the flanks of the profile are produced bysuperposed advance of the tool effected perpendicularly to such mainflank line. In this manner, the basic movement of the dressing tool isalready approximate, to a substantial degree,'to the actual shape of theflank, and therefore additional lateral displacement of the dressingtool or diamond need be effected through only relatively shortadjustment paths. The aforementioned main flank line; which isdetermined geometrically, may be selected for many customary or standardprofiles such as, for example, the profiles of grinding wheels forgenerating roller cutting operations. The selection may be made in asimple manner such that the dressing diamond, during its entireengagement with the grinding wheel along a profile line, is operatedonly with either an increased or forward feed or without any feed.Thereby, reverse feed movements can be avoided in the majority of cases.

A further object of the invention is to provide a means forautomatically controlled dressing of profile grinding Wheels in whichthe grinding wheel profile is produced bytwo dressing diamonds operatingsimultaneously on opposite sides of the grinding wheel and staggered ina circumferential direction, with the feed of the dressing di- .ingtoward the head thereof.

With such a device, each dressing diamond has to follow only one side ofthe entire flank of the profile, and therefore can be easily controlledin the sense mentioned above. Correspondingly, the template forcontrolling the movement of the dressing diamond or diamonds can be of asimple design.

The apparatus in accordance with the invention preferably comprises arack and pinion means connecting the template with the tool slide, and ahydraulic, static powered transmission'system connecting the tracingstylus with the diamond holder, this system always containing a constantvolume of hydraulic fluid such as, for example, oil or the like. Thus,the drive for the main feed of the dressing diamond, and the drive forthe cross feed thereof, are fully separated and two very simple andstrong transmission systems are provided. The rack and pinion means forfeeding the tool slide along such predetermined main flank line can havea relatively simple construction if a particular pinion is coordinatedwith each tool slide, this pinion engaging the respective rack arrangedat the tool slide. The two drive pinions are arranged coaxially and oneof the pinions is mounted on a hollow or tubular shaft through which theshaft of the other pinion is concentrically telescoped. Both pinions cantherefore be turned in opposed directions, and the racks, being arrangedopposite each other on the peripheries of the pinions, can thus bedisplaced in the same direction. By such an arrangement, thesimultaneous feeding of two dressing diamonds, one on each side of thewheel to be dressed, can be eflected.

In accordance with a further concept of the invention, the racks, whichalso form themount'mg slides for the dressing diamonds, can be arrangedfor relative angular adjustment in such a manner that they are inengagement with their respective drive pinions at every angular positioncorresponding to a certain angle of the main flank line. For thispurpose, the racks are mounted slidably on' worm gear segments, andthese worm gear segments can be adjusted conjointly with respect to therequired angle of the main flank line by means of suitable wormoperators. The axes of the worm gear segments are so arranged that theracks are swiveled about the common axis of their drive pinions so thatthe racks always remain in engagement with their respective drivepinions.

With the apparatus of the invention, every tool slide can be adjustedexactly relative to a predetermined main flank line. The commonhydraulic control of the dressing diamonds working on opposite sides ofthe shaping wheel is derived from the tracer stylus sliding along thetemplate and in such a manner that the tracer stylus controls twoseparate hydraulic cylinders, each part a respective separate hydraulicsystem. The volume of hydraulic fluid in both systems is maintainedconstant. However, the effective piston cross section areas of thehydraulic cylinder being actuated by the tracer stylus and that of theother cylinder, which is part of the same hydraulic system but which isconnected with the holder for the diamond, may difier in size. Forexample, it may be advantageous to make the section of the pistondriving the dressing diamond five times as large as that of the pistonconnected with the tracer stylus. In such a case, a reduction ratio of 5to 1, between the displacement of the tracer stylus and the displacementof the diamond, can be achieved. Thus, the template may be magnifiedfive times as respects the profile to be dressed. Such dimensioning ofthe hydraulic system is particularly advantageous because this reductionassures an exceptionally high accuracy of the dressed grinding wheelprofile. Smaller or larger reduction ratios are also possible inaccordance with the profile to be dressed, and the reduction ratios ofthe movement in the direction of the main flank line and that of themovement in a direction perpendicular to the main flank line may bedifferent.

The driving of the template, in accordance with the invention, can alsobe effected hydraulically. The template slide is designed as a rack fromwhich the feed movement of the two tool slides can be derived. At thebeginning and at the end of the path of movement of the template slide,a hydraulic reversal of the diamond holder is effected by actuation oflimit switches by respective stops on the template slide. These limitswitches control electromagnetic valves within the hydraulic drivesystem of the template, and effect the control in such a manner that thevalves, for example at the beginning of the trimming operation, supplypressure fluid under pressure to one end of the drive cylinder of thetemplate in the direction of operation, and simultaneously connect theopposite end of the drive cylinder with an outlet conduit having anadjustable throttle.

The supply of fluid pressure medium to the drive pistons of the diamondtool holders, each of which is designed as a double acting piston, ismaintained constantly and, in each instance, that side of the pistonwhich faces the respective diamond, has pressure fluid delivered theretoby means of a special pressure fluid pump. That is, this pressure tendsto move the diamond tool holder in a direction away from the work. Theopposite surface of the piston of the diamond tool holder is subjectedto a static hydraulic pressure, such as a closed hydraulic system whichcan be termed hydraulic structure or linkage. The control impulses dueto movement of the tracing stylus, and transmitted through the hydraulicpistons connected with the tracing stylus, are transmitted to thelast-mentioned piston surfaces of each diamond holder with a pressurewhich is greater than the counter pressure working upon the other faceof each piston. This assures a working pressure for each of the dressingdiamonds. The drive piston of each tool holder is thus biased in adirection away from the work by the same hydraulic system serving fordriving the template and, when the pressure within the static hydraulicsystem, and transmitting the displacement of the tracing stylus,disappears, each tool holder is displaced in a lifting direction suchthat the dressing diamond therein is disengaged from the work piece.

In such a case, and as soon as the tracing stylus runs off the profileedge of the template when the dressing diamonds are at the end of anoperation, the pressure medium supply to the double acting drivecylinder of the template is reversed by a limit switch operated by thetemplate slide, and this drive cylinder is thus moved reversely toreturn the template to its starting position. The already lifteddiamond, through the medium of its slide connected to the rack of thetemplate by a transmission system, is moved back to its startingposition simultaneously with the retraction of the template, and to thebottom of the profile of the grinding wheel to be dressed.

For an understanding of the principles of the invention, reference ismade to the following description of a typical embodiment thereof asillustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a somewhat schematic sectional view illustrating a cutterreference profile having a certain modulus for a grinding wheel which isto be dressed in accordance with the invention;

FIG. 2 is a front elevation view of apparatus embodying the invention;

FIG. 3 is a side elevation view of the apparatus shown in FIG. 1, with agear box being shown partly in section; and

FIG. 4 is a composite and partly exploded schematic, elevation, plan,and sectional view of apparatus embodying the invention.

Referring to FIG. 1, a grinding wheel 1, of which only the grindingprofile is illustrated, is designed to produce the cutting profile 2,and the wear of the grinding wheel due to the grinding operation, andvarying with location, is designed to be compensated in a known mannerby either constant or intermittent dressing of the grinding wheel bymeans of dressing diamonds 3 and 4 in such a mannerthat the grindingwheel is dressed to its true profile. The flanks of the profile of thegrinding wheel 1 therefore must be dressed to the greatest accuracy bymeans of the dressing diamonds 3 and 4.

If the known template arrangement is used for this purpose, and if thedisplacement of a tracing stylus engaged with the template is used forcontrolling the movement of the dressing diamonds shown in FIG. 1,considerably longer working paths x for the dressing diamonds resultwhen operating, in a known manner, with two tool slides, one of which isdisplaced parallel with the axis of symmetry 5 of the grinding wheelprofile and the other of which is displaced perpendicular to such axisof symmetry. For example, in known arrangements, such displacements aremade with reference to a displacement axis 6 of the longitudinal slideof the known apparatus rather than, as in accordance with the invention,being effected with respect to a reference line 7 hereinafter called themain flank line.

From FIG. 1, it can be seen that a dressing diamond operating, forexample, from a base line 7' parallel to the main flank line 7, andperpendicular to such base line 7' relatively to the flank 8 of drivingwheel 1, has only to cut along the flank and with unchanged clearanceangle, on only a considerably smaller part of its cutting edge than doesthe dressing diamond of the rectangular coordinate system in which oneslide moves parallel to the axis of symmetry 5. A criterion fordetermining the main flank line is that the flank curvatures of theprofile to be dressed change as little as possible in relation to thecutting edge of the diamond, as above described.

Referring to FIG. 2, two dressing diamonds 3 and 4 are operativelyassociated with the grinding wheel, which latter is only partlyillustrated. The two diamonds are arranged in such a manner thatdressing diamond 3 operates on the flank 8 of the grinding wheel anddressing diamond 4 on the flank 12 of the grinding wheel profile. Bothdiamonds 3 and 4, by their respective drive and adjustment devices 9 and10 connected with gear box 11, are moved over the entire respectiveprofile flank associated therewith.

The entire apparatus, of which the individual elements will be furtherexplained and described in connection with FIG. 4, may be mounted, forexample, in a known guide on an upright or column 13 and the apparatusmay be displaced downwards, in the sense of the tool feed, or upwardlyin the sense of retraction from grinding wheel 1, by means of a handwheel 14 on a spindle 15 which, through bevel gears 16 and 17, drives alead screw 18 threaded through a nut 19 secured to column 13.

Referring to FIG. 4, a template slide 20 is designed with a cylinderspace 58 which is closed at its right end by an apertured end member20', and which contains a piston 22 having a pressure medium space 21 tothe left thereof as viewed in FIG. 4. As shown, pressure medium tubes orconduits extend slidably through end wall 20' and through the other endwall adjacent the piston 22, these pressure medium conduits being fixedat their outer ends. During displacement of the slide in the directionof arrow 23, template 24 is moved to the right past the tracing stylus26 which is in engagement with the profile edge 25 of template 24. Thisprofile edge is magnified or enlarged in accordance with the desiredreduction ratio of the reduction gearing which will be described.Tracing stylus 26 is displaced in accordance with the contours ofprofile 25.

During advance of template slide 20, rack 27 which is fixed therewithrotates a pinion 28 which, through pinion 29 and spur gear 30, drives apinion 31 engaged with a rack 33. The interconnection between spur gear30 and pinion 31 is designed as a tubular shaft concentrically orcoaxially receiving a shaft or axle 75. A pinion 31 engaged with asecond rack 32 facing oppositely to rack 33 is driven from gear wheel 28through pinion 29 and spur gear 30', the latter being secured to shaft75 as is also the pinion 31'. Due to the coaxial shaft 75 and tubularshaft interconnecting the elements 30 and 31, pinions 31 and 31' can berotated, about a common axis, in opposite directions, so that racks 32and 33, which are in opposition to each other, can be moved in the samedirection. Such movement of racks 32 and 33 in the same direction may beeffected, for example, by means of an intermediate pinion 76interengaged between pinion 29' and spur gear 30. In accordance with theinvention, the gearing 29-30 can be made interchangeable so as to changethe reduction ratio as desired.

In FIG. 4, tool slides 34 and 35 are shown in their uppermost positionwhich they occupy at the end of a trimming operation, and stylus 26 isillustrated as at the left or termination end of profile edge 25 oftemplate 24.

During advance of template 24, pistons 37 and 38, interconnected by across head 36, are conjointly displaced in the direction of an arrow 39,thereby displacing the fluid pressure medium in cylinders 40 and 41.This pressure fluid medium is also in communication with the cylinderspace 48 of tool holder 49 (9) for dressing diamond 3 and thecorresponding space of tool holder 50 (10 for diamond 4. Suchintercommunication is provided by the conduits 42 and 43, thecompensating cylinders 44 and 45, and the conduits 46 and 47.

The displaceable portion 52 of tool holder 49 (9), which carries diamond3 and which is connected with piston 51, is therefore displaced in thedirection of arrow 53, and a similar displacement takes place withrespect to the displacement portion of the tool holder 50 (10) fordiamond 4. Inasmuch as both hydraulic transmission systems have aconstant volume of pressure fluid medium between cylinders 40 and 41 andthe cylinder spaces such as 48, diamonds 3 and 4 follow everydisplacemment of stylus 26 with the greatest accuracy. Furthermore,since the effective surface of piston 51, as illustrated in FIG. 4, isfive times as large as that of piston 37, each displacement of stylus 26is reduced by a factor of five when transmitted to dressing diamonds 3and 4.

Hydraulic control of the start and finish of the operation, inaccordance with a further feature of the invention, is effected in thefollowing manner. During the dressing operation, a right-hand stop 54 ontemplate slide 20 actuates a limit switch 55 which, through circuitswhich are not shown in the drawing, reverses the position of twoelectromagnetic valves 56 and 57 in such a manner that the left cylinderspace 21 within template slide 50 is connected to a pump 62 for thefluid pressure medium through a throttle valve 70, the electromagneticvalve 57, and a conduit 61. Therefore, template slide 20 returns in thedirection of arrow 63 and, furthermore, stylus 26, due to the dualpistons 37, 38 having lost the pressure of conduit 64, is disengaged orretracted from profile edge of template 24in the direction of arrow 65.The pistons, such as 51, of tool holders 49 and 50 are displaced in thedirection of arrow 66 (66'), and thus diamonds 3 and 4 are retractedfrom the work to be dressed. The pressure in cylinder space 48, due tothe retraction of stylus 26 from profile edge 25 and template 24, is nowless than the counter-pressure.

correspondingly, the reversing of the system to commence the nexttrimming operation is effected by means of a left-hand stop 68, on slide20, operating a limit switch 69. Due to the further reversal of thepositions of the electromagnetic valves, the dual pistons of stylus 26are subjected to the pressure of the fluid pressure medium throughconduit 64, and this pressure fluid medium presses stylus 26 to engagetemplate 24. At the same time, diamond 3 is pressed, through piston 51and conduit 47,

in the direction of arrow 53 to engage the grinding wheel in accordancewith the particular profile of template 24. The counter pressure onpiston 51 is maintained through conduit 67 in order to provide therequired accuracy for the system through back pressure bias.

At this time, the pressure acting on the dual pistons and stylus 26 isgreater than the back bias pressure acting on piston 51 through conduit67. Cylinder space 58, after the aforementioned reversal of valves 56and 57, and through conduit 59, valve space 60, and conduit 61, issubjected to the pressure of pump 62. Template slide 20 is thendisplaced in the direction of the arrow 23 or in the operatingdirection. By means of throttle valve 70, it is possible, in a simplemanner, to adjust the rate of oil flow out of cylinder space 21 andthereby control the timing of the operation as desired.

The inclination of the tool slides 34 and 35 may be adjusted todetermine the starting line for the hydraulically effected displacementmovements of dressing diamonds 3 and 4, and this inclination ispredetermined in correspondence with the main flank line as earlierdefined. Such inclination adjustment is effected by means of two wormgear segments 71 and 72 and worms 73 and 74, respectively, engagedtherewith. Worm gear segments 71 and 72 are coaxial with the common axisof pinions 31 and 31' at any angular position. Thus, racks 32 and 33 arein engagement with the pinions 31 and 31' in all angular positions ofthe longitudinal axes of tool slides 34 and 35. Thereby, a perfect driveof tool slides 34 and 35 from rack 27 of template slide 20 is assured.

In the position of the hydraulic system shown in FIG. ,4, the workingstroke corresponds to template slide 20 moving in the direction of arrow23. A reversal of direction, as indicated by arrow 63, has not yet beeneffected. The direction of flow of the fluid pressure medium is shown bythe several arrows in the interconnecting conduits.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that' the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a tool holder slidably supported in said toolslide for displacement in a direction perpendicular to the direction ofdisplacement of said tool slide; a longitudinally displaceable templateslide spaced from said tool slide and arranged to have templatesinterchangeably secured thereon; a stylus cooperable with a profilededge of a template on said template slide; mechanical transmission meansinterconnecting said tool slide and said template slide for coordinatedmovement; and a hydraulic fluidfilled line directly interconnecting saidstylus and said tool holder for coordinated movement of said stylus andsaid tool holder.

2. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a tool holder slidably supported in said toolslide for displacement in a direction perpendicular to the direction ofdisplacement of said tool slide; a longitudinally displaceable templateslide arranged to have templates interchangeably secured thereon; astylus cooperable with a profiled edge of a template on said templateslide; mechanical transmission means interconnecting said tool slide andsaid template slide for coordinated movement; a hydraulic transmissionmeans interconnecting said stylus and said tool holder for coordinatedmovement of said stylus and said tool holder; said hydraulictransmission means being a static power transmission system having aconstant volume of fluid pressure medium therein; and means maintaininga constant back pressure on said tool holder resisting movement thereofby said stylus through said static power transmission system.

3. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a longitudinally displaceable tool holderslidably mounted in said tool slide for displacement in a directionperpendicular to the direction of displacement of said tool slide; alongitudinally displaceable template slide arranged to have templatesinterchangeably secured thereon; a displaceable stylus cooperable with aprofiled edge of a template secured on said template slide; rack andpinion means mechanically interconnecting said tool slide and saidtemplate slide for conjoint longitudinal displacement, said rack andpinion transmission means including speed reduction means; and hydraulictransmission means interconnecting said stylus and said tool holder forconjoint displacement of said tool holder in accordance with thedisplacement of said stylus.

4. Apparatus for automatically controlled dressing of profile grindingWheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a longitudinally displaceable tool holderslidably mounted in said tool slide for displacement in a directionperpendicular to the direction of displacement of said tool slide; alongitudinally displaceable template slide arranged to have templatesinterchangeably secured thereon; a displaceable stylus cooperable with aprofiled edge of a template secured on said template slide; rack andpinion means mechanically interconnecting said tool slide and saidtemplate slide for conjoint longitudinal displacement, said rack andpinion transmission means including speed reduction means; and hydraulictransmission means interconnecting said stylus and said tool holder forconjoint displacement of said tool holder in accordance with thedisplacement of said stylus; said hydraulic transmission means providinga relative reduction of displacement of said tool holder with respect tosaid stylus.

5. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a longitudinally displaceable tool holderslidably mounted in said tool slide for displacement in a directionperpendicular to the direction of displacement of said tool slide; alongitudinally displaceable template slide arranged to have templatesinterchangeably secured thereon; a displaceable stylus cooperable with aprofiled edge of a template secured on said template slide; rack andpinion means mechanically interconnecting said tool slide and saidtemplate slide for conjoint longitudinal displacement, said rack andpinion transmission means including speed reduction means; and hydraulictransmission means interconnecting said stylus and said tool holder forconjoint displacement of said tool holder in accordance with thedisplacement of said stylus; said hydraulic transmission means providinga relative reduction of displacement of said tool holder with respect tosaid stylus; the reduction ratio of said rack and pinion mechanicaltransmission differing from the reduction ratio of said hydraulictransmission means.

6. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a longitudinally displaceable tool holderslidably mounted in said tool slide for displacement in a directionperpendicular to the direction of displacement of said tool slide; alongitudinally displaceable template slide arranged to have templatesinterchangeably secured thereon; a displaceable stylus cooperable withthe profiled edge of a template secured on said template slide; rack andpinion transmission means mechanically interconnecting said tool slideand said template slide for conjoint longitudinal displacement, saidrack and pinion transmission means including speed reduction means; andhydraulic transmission means interconnecting said stylus and said toolholder for conjoint displacement of said tool holder in accordance withthe displacement of said stylus; said hydraulic transmission meansproviding a relative reducuction of displacement of said tool holderwith respect to said stylus; the reduction ratio of said rack and piniontransmission means differing from the reduction ratio of said hydraulictransmission means; said rack and pinion transmission means includinginterchangeable gear components whereby the speed reduction thereof canbe preselected as desired.

7. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a pair oflongitudinally displaceable tool slides each associated with arespective dressing diamond, with the diamonds operating on respectiveopposite flanks of the grinding wheel; a pair of racks, each secured toa respective tool slide; a pair of coaxial pinions, each engaged with arespective rack; a longitudinally displaceable template slide arrangedto have templates interchangeably mounted thereon; reduction gearinginterconnecting said template slide and said pinion for conjointoperation of said tool slides in accordance with displacement of saidtemplate slide, said reduction gearing rotating said coaxial pinions inopposed directions; means mounting said tool slides for angularadjustment about the common axis of said coaxial pinions for adjustmentof the direction of displacement of said tool slides; a pair of toolholders, each mounted in a tool slide for longitudinal displacement in adirection substantially perpendicular to the direction of displacementof the associated tool slide; a stylus engageable with a profiled edgeof a template mounted on said template slide; and means interconnectingsaid stylus and said tool holders for conjoint displacement of said toolholders in accordance with displacement of said stylus along saidprofiled template edge.

8. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a pair oflongitudinally displaceable tool slides each associated with arespective dressing diamond, with the diamonds operating on respctiveopposite flanks of the grinding wheel; a pair of racks, each secured toa respective tool slide; a pair of coaxial pinions, each en- |gaged witha respective rack; a longitudinally displaceable template slide arrangedto have templates interchangeably mounted thereon; reduction gearinginterconnecting said template slide and said pinions for conjointoperation of said tool slides in accordance with displacement of saidtemplate slide, said reduction gearing rotating said coaxial pinions inopposed directions; means mounting said tool slides for angularadjustment about the common axis of said coaxial pinions for adjustmentof the direction of displacement of said tool slides; a pair of toolholders, each mounted in a tool slide for longitudinal displacement in adirection substantially perpendicular to the direction of displacementof the associated tool slide; a stylus engageable with a profiled edgeof a template mounted on said template slide; and a hydraulictransmission system interconnecting said stylus and said two toolholders for conjoint displacement of said tool holders in correspondencewith the displacement of said stylus by said profiled template edge.

9. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a pair oflongitudinally displaceable tool slides each associated with arespective dressing diamond, with the diamonds operating on respectiveopposite flanks of the grinding wheel; a pair of racks, each secured toa respective tool slide; a pair of coaxial pinions, each engaged with arespective rack; a longitudinally displaceable template slide arrangedto have templates interchangeably mounted thereon; reduction gearinginterconnecting said template slide and said pinions for conjointoperation of said tool slides in accordance with displacement of saidtemplate slide; said reduction gearing rotating said coaxial pinions inopposed directions; means mounting said tool slides for angularadjustment about the common axis of said coaxial pinions for adjustmentof the direction of displacement of said tool slides; a pair of toolholders, each mounted in a tool slide for longitudinal displacement in adirection substantially perpendicular to the direction of displacementof the associated tool slide; a stylus engageable wth a profiled edge ofa template mounted on said template slide; and means interconnectingsaid stylus and said tool holders for conjoint displacement of said toolholders in accordance with displacement of said stylus along saidprofiled template edge, said means mounting said tool slides for angulardisplacement comprising a pair of worm gear segments angularlydisplaceable about said common axis of said coaxial pinions, and a pairof worms, each meshing with a respective Worm gear segment, operable toindependently adjust the relative angular orientation of the associatedtool slide.

10. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a pair oflongitudinally displaceable tool slides each associated with arespective one of a pair of dressing diamonds, each diamond beingoperatively associated with a respective opposite flank of the grindingwheel to be dressed; a pair of tool holders each slidably mounted in atool slide for longitudinal displacement in a direction perpendicular tothe direction of longitudinal displacement of the associated tool slide;a longitudinally displaceable template slide arranged to have templatesinterchangeably supported thereon; transmission means interconnectingsaid template slide and said tool slides for conjoint displacement ofsaid tool slides in accordance with longitudinal displacement of saidtemplate slide; a stylus arranged to engage the profiled edge of atemplate mounted on said template slide; a pair of first fluid pressureactuators each including a displaceable memher, said displaceablemembers being rigidly interconnected and connected to said stylus formovement with said stylus; a pair of second fluid pressure actuatorseach associated with a respective tool holder to effect longitudinaldisplacement thereof; and separate hydraulic transmission systems eachinterconnecting a respective first hydraulic actuator to a respectivesecond hydraulic actuator.

11. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a tool holder slidably supported in said toolslide for displacement in a direction perpendicular to the direction ofdisplacement of said tool slide; a longitudinally displaceable templateslide arranged to have templates interchangeably secured thereon; astylus cooperable with a profiled edge of a template on said templateslide; mechanical transmission means interconnecting said tool slide andsaid template slide for coordinated movement; a hydraulic actuator fordisplacing said template slide in a tool feeding direction; hydraulicactuator means maintaining said stylus engaged with said profiledtemplate edge; means operable to adjust the rate of displacement of saidtemplate slide by said hydraulic actuator; and a hydraulic fluid-filledline directly interconnecting said stylus and said tool holder forcoordinated movement of said stylus and said tool holder.

12. Apparatus for automatically controlled dressing of profile grindingwheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a tool holder slidably supported in said toolslide for displacement in a direction perpendicular to the direction ofdisplacement of said tool slide; a longitudinally displaceable templateslide arranged to have templates interchangeably secured thereon; astylus cooperable with a profiled edge of a template on said templateslide; mechanical transmission means interconnecting said tool slide andsaid template slide for coordinated movement; a hydraulic actuator fordisplacing said template slide in a tool feeding direction; hydraulicactuator means maintaining said stylus engaged with said profiledtemplate edge; a hydraulic transmission system for said actuator andsaid actuator means, said hydraulic transmission system maintaining apositive pressure for one direction of operation of said hydraulicactuator and said hydraulic actuator means; and means maintaining aconstant back bias pressure opposing said positive pressure; saidhydraulic transmission system including a hydraulic fluidfilled linedirectly interconnecting said stylus and said tool holder forcoordinated movement of said stylus and said tool holder.

13. Apparatus for automatically controlled dressing of profile grindingWheels by dressing diamonds comprising, in combination, a longitudinallydisplaceable tool slide; a tool holder slidably supported in said toolslide for displacement in a direction perpendicular to the direction ofdisplacement of said tool slide; a longitudinally displaceable templateslide arranged to have templates interchangeably secured thereon; astylus cooperable with a profiled edge of a template on said templateslide; mechanical transmission means interconnecting said tool slide andsaid template slide for coordinated movement; a hydraulic actuator fordisplacing said template slide in a tool feeding direction; hydraulicactuator means maintaining said stylus engaged with said profiledtemplate edge; a hydraulic transmission system for said actuator andsaid actuator means, said hydraulic transmission system maintaining apositive pressure for one direction of operation of said hydraulicactuator and said hydraulic actuator means and a constant back biaspressure opposing said positive pressure; electromagnetically operatedvalves controlling application of said positive pressure to saidhydraulic actuator and said hydraulic actuator means; switch meansoperable to reverse the positions of said electromagnetically operatedvalves; and stop means on said template slide elfective to operate arespective one of said switch means at each limit of displacement ofsaid template slide.

References Cited UNITED STATES PATENTS 2,248,463 7/ 1941 Ott 112,602,437 7/ 1952 Tancred 12511 3,067,733 12/ 1962 Pernack 125-11FOREIGN PATENTS 240,933 10/ 1925 Great Britain. 397,718 8./ 193 3 GreatBritain. 806,629 12/ 1958 Great Britain.

HAROLD D. WHITEHEAD, Primary Examiner.

1. APPARATUS FOR AUTOMATICALLY CONTROLLED DRESSING OF PROFILE GRINDINGWHEELS BY DRESSING DIAMONDS COMPRISING, IN COMBINATION, A LONGITUDINALLYDISPLACEABLE TOOL SLIDE; A TOOL HOLDER SLIDABLY SUPPORTED IN SAID TOOLSLIDE FOR DISPLACEMENT IN A DIRECTION PERPENDICULAR TO THE DIRECTION OFDISPLACEMENT OF SAID TOOL SLIDE; A LONGITUDINALLY DISPLACEABLE TEMPLATESLIDE SPACED FROM SAID TOOL SLIDE AND ARRANGED TO HAVE TEMPLATESINTERCHANGEABLE SECURED THEREON; A STYLUS COOPERABLE WITH A PROFILEDEDGE OF A TEMPLATE ON SAID TEMPLATE SLIDE; MECHANICAL TRANSMISSION MEANSINTERCONNECTING SAID TOOL SLIDE AND SAID TEMPLATE SLIDE FOR COORDINATEMOVEMENT; AND A HYDRAULIC FLUID-